Microprocessor controllable automatic sampler

Abstract

An apparatus for automatically establishing fluid communication between a probe and a plurality of containers presented in the sequence to a sampling position includes a container supported rack movable into and out of the sampling position. A probe holder supports the probe for movement into and out of the sampling position. A drive unit connects to the rack and probe holder for effecting and controlling the movements thereof. The drive unit includes a first pressure fluid operated motor actuable for moving the probe into and out of the sampling position for communication with a container thereat and a second pressure fluid operated motor actuable for causing the rack to move a desired one of the containers into the sampling position, the first and second pressure fluid operated motors being actuable independently of each other from a common source of pressure fluid. The apparatus is connectible to provide sequential samples for an analysis system, such as a high pressure liquid chromatography system. In a preferred embodiment the sampler apparatus includes an onboard microprocessor circuit programmable to control sequencing of the pressure fluid motors and timing of the chromatography system. This is in addition to an external computer for processing information resulting from analysis of the samples provided by the sampler apparatus.

The embodiments of the invention in which an exclusive property or privileged is claimed are defined as follows: 
     
       1. An apparatus for automatically establishing fluid communication between probe means and a plurality of containers presented in a controlled sequence to a sampling position, comprising: rack means adapted to hold said containers for movement into and out of said sampling position;   hollow probe means supported by probe holding means and movably thereby into and out of said sampling position; and   drive means connected to said rack means and to said probe holding means for effecting and controlling said movements thereof, said drive means including a first pressure fluid operated motor actuable for moving said probe means into and out of said sampling position for communication with containers thereat, and a second pressure fluid operated motor actuable for causing said rack means to move a desired one of said containers to said sampling position, said first and second pressure fluid operated motors being actuable independently of each other from a common source of pressure fluid, said first motor comprising a first pressure fluid cylinder actuable to move said probe means vertically, said first pressure fluid cylinder having a casing upstanding within said housing and a piston rod vertically reciprocable by pressure fluid, said second motor comprising a second pressure fluid cylinder with a casing horizontally extending from and supported on a vertical pivot axis fixed on said housing and a piston rod extending generally tangentially of said first pressure fluid cylinder and operatively connected to said first pressure fluid cylinder, and means for horizontally moving both said probe means and rack means for shifting said probe means between said sampling position and a rinse position, and for advancing said rack means to bring another container to said sampling position.   
     
     
       2. The apparatus of claim 1, including a housing, said rack means and probe means and sampling position being atop said housing, said first and second cylinders being within said housing, said housing containing solenoid valves through which said cylinders are connectible with said common pressure fluid source, a microprocessor circuit mounted within said housing adjacent said solenoid valves and connected through said solenoid valves for controlling all movements of said cylinders. 
     
     
       3. The apparatus of claim 1, including arm means pivoted on said upstanding first pressure fluid cylinder casing and having an outboard portion pivotally connected to said second pressure fluid cylinder for pivoting said arm means about the axis of said first pressure fluid cylinder in response to extension and retraction of said second pressure fluid cylinder and connected to support said probe means for pivoting of the latter therewith, ratchet arm means also pivotally connected with said outboard portion of said arm means for reciprocation thereby, means resiliently guiding said reciprocation of said ratchet arm means and a sprocket engaged by and responsive to reciprocation of said ratchet arm means for causing said rack means to advance containers to said sampling position. 
     
     
       4. The apparatus of claim 3, in which said rack means comprises a sample tray fixed coaxially to said sprocket by means supported for rotation about a vertical axis in said housing and protruding upward therethrough, and including detent means fixedly supported in said housing and cooperating with said sprocket for resiliently locating containers on said sample tray repeatably at said sampling position and holding same there prior to circumferential advancement of said sprocket by a reciprocation stroke of said ratchet arm means by said second pressure fluid cylinder. 
     
     
       5. The apparatus of claim 1, including a further pressure fluid cylinder horizontally fixed on said housing and actuable to interpose a wedge in the path of the piston rod of said second pressure fluid cylinder to reduce the horizontal range of swing of said probe means toward the rack means and thereby produce a second sampling position, said rack means comprising a rotationally movable sample tray having concentric first and second rings of container locations thereon, said first ring being surrounded by the second and passing through said first sampling position, said second sampling ring passing through said second sampling position. 
     
     
       6. The apparatus of claim 1, including a dash pot fixed within said housing opposite said second pressure fluid cylinder, arm means pivotable on said first pressure fluid cylinder casing and with an outboard portion pivotally connected to said second pressure fluid cylinder for pivoting thereby and located to abut said dash pot as said second pressure fluid cylinder nears the end of its extension, said arm means being connected to produce horizontal movement of said probe means between a rinse position and said sampling position and to advance said rack means. 
     
     
       7. The apparatus of claim 1, including arm means pivotable on said first pressure fluid cylinder casing and having an outboard portion swingable about said first pressure fluid cylinder casing, said outboard portion being pivotally connected to said second pressure fluid cylinder for pivoting said arm means thereby, said outboard portion being pivotally connected to ratchet arm means for stepwise moving of said rack means, said outboard portion including a first upstanding rod radially remote from said first pressure fluid cylinder casing and effecting said pivotal connection to said second pressure fluid cylinder and ratchet arm means adjacent the lower end thereof, a second upstanding rod radially spaced between said first upstanding rod and said first pressure fluid cylinder casing, a sample head fixed at one end to the upstanding piston rod of said first pressure cylinder for raising and lowering thereby and fixedly carrying said probe means at the remote end thereof, the upper end of said second upstanding rod being fixed to said sample head intermediate the ends of the latter for horizontally pivoting said sample head with said arm means, said second upstanding rod being slidable up and down with respect to said arm means for maintaining alignment of said sample head with said arm means during vertical reciprocation of said first pressure fluid cylinder, said first upstanding rod being vertically fixed with respect to said arm means and pivotally connecting said arm means with said ratchet arm means and second pressure fluid cylinder, said first upstanding rod carrying at its upper end, for pivotal adjustment about the axis of said first upstanding rod, sample stripper means including a sample stripper arm disposed along the vertical path of movement of said probe means for vertically guiding and stripping of containers from said probe means during vertical movement of said probe means with respect thereto and for horizontal pivoting with said probe means, said first upstanding rod being vertically fixed with respect to said arm means. 
     
     
       8. An apparatus for automatically establishing fluid communication between probe means and a plurality of containers presented in a controlled sequence to a sampling position, comprising: rack means adapted to hold said containers for movement into and out of said sampling position;   hollow probe means supported by probe holding means and movable thereby into and out of said sampling position; and   drive means connected to said rack means and to said probe holding means for effecting and controlling said movements thereof, said drive means including a first pressure fluid operated motor actuable for moving said probe means into and out of said sampling position for communication with containers thereat, and a second pressure fluid operated motor actuable for causing said rack means to move a desired one of said containers to said sampling position, said first and second pressure fluid operated motors being actuable independently of each other from a common source of pressure fluid, said first pressure fluid actuated motor comprising independently actuable horizontal and vertical pressure fluid cylinders for horizontally pivoting and vertically shifting said probe means, said second pressure fluid actuated motor comprising at least one further pressure fluid cylinder and ratchet arm means reciprocated thereby, said rack means comprising a rotatable sample tray and a sprocket in fixed rotationally driving relation with said sample tray and engageable by said ratchet arm means for circumferentially incrementing said sample tray by reciprocation of said further pressure fluid cylinder.   
     
     
       9. An apparatus for automatically establishing fluid communication between probe means and a plurality of containers presented in a controlled sequence to a sampling position, comprising: rack means adapted to hold said containers for movement into and out of said sampling position;   hollow probe means supported by probe holding means and movable thereby into and out of said sampling position, and drive means connected to said rack means and to said probe holding means for effecting and controlling said movements thereof;   a housing containing said drive means and surmounted by said rack means and probe means;   a center mounting block fixed within said housing and flanked in spaced relation by a horizontally fixed, vertically extensible pressure fluid cylinder and a horizontally fixed vertical axis support on which said rack means is rotatably supported;   a contact finger bracket fixed atop said center mounting block and coactive with a binary disk rotatable in fixed relation with said rack means for identifying containers presented to said sampling position;   a sprocket rotatable with said rack and ratchet arm means extending between said vertically extensible pressure fluid cylinder and adjacent one end thereof and having an opposite end engageable with teeth of said sprocket for circumferentially incrementing said rack means, said center mounting block including means resiliently guiding the central portion of said ratchet arm means for reciprocation therethrough;   detent means on said center mounting block for engaging said sprocket to precisely align a container thereon with the sampling position and to prevent unintended rotation of said rack means in the absence of actuation by said ratchet arm means.   
     
     
       10. The apparatus of claim 9, in which said rack means comprises a sample tray having radially inner and outer rings of container locations thereon, a horizontal pressure fluid cylinder having an extensible portion and extending adjacent said center mounting block and engageable with a pivot arm for reciprocably driving said ratchet arm means, means supporting said probe means for pivoting with said pivot arm in response to reciprocation of said horizontal pressure fluid cylinder, and including a further horizontal pressure fluid cylinder supported on said center mounting block and extensible to insert a wedge into the path of the extensible portion of said first mentioned horizontal pressure fluid cylinder to change one end of the stroke range thereof and thereby cause the probe means to swing to a sampling position on the outer rather than the inner ring of containers of said rack means. 
     
     
       11. The apparatus of claim 10, including means fixing said vertically extensible pressure cylinder and center mounting block on a floor surface low in said housing, and including first, second, and third electrically actuable pressure fluid flow control valves upstanding from said floor surface adjacent to, and controlling pressure fluid flow to, said vertically extensible pressure fluid cylinder, said first mentioned horizontal pressure fluid cylinder and said further horizontal pressure fluid cylinder, a fourth electrically actuated pressure fluid control valve upstanding from said floor surface, and an automatic injection valve mounted on said housing and supplied pressure fluid under control of said fourth valve for controlling positioning of said automatic injection valve, said automatic injection valve controlling liquid flow from said probe means to selected locations for sample analysis or rinse liquid disposal. 
     
     
       12. An apparatus for automatic sampling of containers presented in a controlled sequence to a sampling position, comprising: a housing;   rack means adapted to hold said containers for movement into and out of said sampling position;   hollow probe means supported by probe holding means and movable thereby into and out of said sampling position;   motor means within said housing and connected to said rack means and to said probe holding means for effecting and controlling said movements thereof;   a microprocessor circuit mounted within said housing adjacent said motor means and connected thereto for controlling movements of said motor means in a preselectable sequence, said housing including exterior front and rear panels, said exterior front panel carrying manually settable control data inputs and information display means, interior front and rear panels disposed within said housing respectively adjacent said exterior front and rear panels, said motor means being pneumatic and being disposed between said interior panels, said interior front panel mounting said microprocessor circuit, connecting means between said front panels for interconnecting said microprocessor circuit with said control data inputs and information display means on said exterior front panel, a circuit voltage supply mounted in said housing adjacent said interior front panel for supplying operating potential to said microprocessor circuit thereon, an external voltage supply input connection on said exterior rear panel, controllable relay means mounted on said interior rear panel and controllable for applying said external voltage to operate said motor means, conductor means connecting control inputs of said controllable relay means to outputs of said microprocessor circuitry on said interior front panel.   
     
     
       13. The apparatus of claim 12, in which said motor means includes solenoid valves and pneumatic motors driven thereby and in turn defining the sole motor power sources for said rack means and probe means, said circuit voltage supply being a low dc voltage supply, said external voltage being an ac voltage, said controllable means being solid state ac controlling relays controllable for applying ac operating potential to said solenoid valves and having dc control inputs controlled by said microprocessor circuitry. 
     
     
       14. Apparatus for automatic sampling of containers presented in a controlled sequence to a sampling position, comprising: a housing;   a rack adapted to hold said containers and mounted for moving of said containers into and out of the sampling position;   a hollow probe supported by probe holding means and movable into and out of the sampling position;   motor means within the housing and connected to the rack means and to the probe holding means for effecting and controlling the movements thereof;   a microprocessor circuit mounted within said housing adjacent the motor means and connected thereto for controlling movements of said motor means in a preselectable sequence, said microprocessor circuit including a programmed microprocessor;   front panel switches mounted on the front panel of said housing and manually actuable for applying to the microprocessor the number of the last position on said rack to be sampled, and the duration of sample time, chromatography time and rinse time intervals to be timed by said microprocessor circuit;   rack position means disposed adjacent said rack for sensing the instantaneous position thereof and applying to said microprocessor a digital signal pattern indicating instantaneous portion of the rack, said front panel carrying a digital display driven by said microprocessor and indicating the instantaneous position of said tray;   a digital display on said front panel indicating the time remaining in the then running one of said sample time, chromatography time and rinse time intervals, said time remaining display being driven by an output of said microprocessor, the microprocessor having a plurality of control outputs;   a chromatography column and detector connected with a recorder to indicate the results of a chromatography measurement by the column;   means providing an output event marker from said microprocessor to said recorder to differentiate between recordings for different samples fed to said column;   a sampling valve loadable with a quantity of sample from a given container on said rack and actuable for applying said quantity of sample of said column and pump means for transferring said quantity of sample from said container on said rack through said sampling valve to said column;   means controlling operation of said pump means, recorder and sampling valve in response to said last-mentioned outputs of said microprocessor to cycle same through said sample time, chromatography time and rinse time for each container sampled by said hollow probe means, said last-mentioned outputs of said microprocessor also being connected to control sequencing of said rack means and hollow probe means in coordination with said pump means, recording and sampling valve.   
     
     
       15. The apparatus of claim 14, including an external computer interface, lines for transferring from said microprocessor to said external computer interface sample identification data and signals indicating the time at which a sample is injected into the column, a line from said external computer interface to said microprocessor for providing an enable signal when an external computer is ready to receive data from the microprocessor, means providing the output from said detector to said external computer interface for directly providing detector output analog data thereto for processing by the external computer in relation to the sample identification data provided by said microprocessor, such that an external computer can be used for generation of reports, for storing test data, and similar uses, but wherein said microprocessor in said housing controls both sampling of said containers on said rack and operation of said chromatography column and detector.